Add accept4() syscall

Add accept4() using SYSCALLS.TXT and gensyscall

Change-Id: I6f19f29144186d15d46423e10f2cc4b4223719c6
diff --git a/libc/arch-mips64/syscalls/accept4.S b/libc/arch-mips64/syscalls/accept4.S
new file mode 100644
index 0000000..8b5cadb
--- /dev/null
+++ b/libc/arch-mips64/syscalls/accept4.S
@@ -0,0 +1,25 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(accept4)
+    .set push
+    .set noreorder
+    li v0, __NR_accept4
+    syscall
+    bnez a3, 1f
+    move a0, v0
+    j ra
+    nop
+1:
+    move t0, ra
+    bal     2f
+    nop
+2:
+    .cpsetup ra, t1, 2b
+    LA t9,__set_errno
+    .cpreturn
+    j t9
+    move ra, t0
+    .set pop
+END(accept4)